I've paired Bluetooth to my Fiat 500 2012 car just yesterday. I purchased the Emcomgear USB adapter for just $10 from Amazon, and within a minute or two was paired. The sound was excellent coming from my Archos 5. The Emcomgear appeared on my Archos 5 paired list as dmzgear and when selected the Archos audio appeared immediately on my Fiat.
ECOMGEAR USB Bluetooth Audio Music Receiver Adapterhttp://www.amazon.com/gp/product/B0083D ... 03_s00_i00
That's an excellent price. Also from Amazon, I bought the Samsung Stereo Bluetooth headset HS3000. It has a built-in rechargeable battery that's good for about 6 or 7 hrs. At the time of this writing, it sells for $34, which includes the AC charger, and a pair of earbuds. The included charger uses a standard micro-usb connector (commomly used in many smart phones) for use in the home with AC adapter. Along with my Archos charging cable (standard USB to micro-USB cable), I am able to charge the HS3000 with my generic USB cigarette lighter accessory in the car.
Works great with A5 whiled paired up to the HS3000 for use in my car stereo (via 3.5 millimeter male-to-male cable). I noticed that when I pair the HS3000 with my iPhone (for playing iPod music over the car speakers) I have to shut down the volume in the car stereo when I get an incoming call, so that the caller on the other end doesn't hear the voice delay that gets picked up over the car speakers.http://www.amazon.com/Samsung-Stereo-Bluetooth-Headset-HS3000/dp/B0057WWK5E/ref=sr_1_1?s=electronics&ie=UTF8&qid=1345569905&sr=1-1&keywords=hs3000+bluetooth+stereo+headset+kit
Unfortunately, both excess heat (from the sun) and shock/vibration (from the road) can damage or shorten the life of the hard drive in these A5's. For this reason, I rarely use my Archos car mount (windshield).